According to the conventional an electric motor driven toggle mold clamping device, a scattering of a lubricant from a rotating ball nut member is prevented by covering a nut cover to a circumference of the ball nut member (JP2003-083416). Also, in another conventional device, the scattering of the grease mist from the rotating ball nut member is prevented by providing a cover plate to a toggle support (JP3199363).